#include "Date.h"

bool Date::operator==(const Date& d) const 
{
    return _year == d._year &&
           _month == d._month &&
           _day == d._day;
}
bool Date::operator!=(const Date& d) const 
{
    return !(*this == d);
}
bool Date::operator>(const Date& d) const 
{
    if (_year > d._year)
    {
        return true;
    }
    else if (_year == d._year && _month > d._month)
    {
        return true;
    }
    else if (_year == d._year && _month == d._month && _day > d._day)
    {
        return true;
    }

    return false;
}
bool Date::operator>=(const Date& d) const 
{
    return *this > d || *this == d;
}
bool Date::operator<(const Date& d) const 
{
    return !(*this >= d);
}
bool Date::operator<=(const Date& d) const 
{
    return !(*this > d);
}
    
Date& Date::operator+=(int day)
{
    _day += day;

    while (_day > GetMonthDay(_year, _month))
    {
        _day -= GetMonthDay(_year, _month);
        _month ++ ;

        if (_month == 13)
        {
            _month = 1;
            _year ++ ;
        }
    }

    return *this;
}

Date Date::operator+(int day)
{
	Date tmp(*this);
	tmp += day;
	return tmp;
}

Date Date::operator-(int day)
{
	Date tmp(*this);
	tmp -= day;

	return tmp;
}
Date& Date::operator-=(int day)
{
	if (day < 0)
	{
		return *this += -day;
	}

	_day -= day;
	while (_day <= 0)
	{
		_month--;
		if (_month == 0)
		{
			_month = 12;
			_year -- ;
		}
		_day += GetMonthDay(_year, _month);
	}

	return *this;
}

Date& Date::operator++() // 前置++
{
	return *this += 1;
}
Date Date::operator++(int) // 后置++
{
	Date tmp(*this);
	*this += 1;

	return tmp;
}
Date& Date::operator--() // 前置++
{
	return *this -= 1;
}
Date Date::operator--(int) // 后置++
{
	Date tmp(*this);
	*this -= 1;

	return tmp;
}

int Date::operator-(const Date& d) const  // 两个日期相差多少天
{
	int flag = 1;
	Date min = d;
	Date max = *this;

	if (*this < d)
	{
		min = *this;
		max = d;
		flag = -1;
	}

	int count = 0;
	while (min != max)
	{
		++min;
		++count;
	}

	return count;
}
